Emulsions Are Water-Based Heroes for Acne-Prone Skin

If you've ever taken a chemistry class, you've likely heard the term "emulsion." Defined as "a mixture of two or more liquids in which one is present as droplets, of microscopic or ultramicroscopic size, distributed throughout the other," the term is also appropriately used to describe lightweight, water-based moisturizers. Long-celebrated in the K-beauty world, emulsions promise the hydration that comes with a cream or serum but without the heavy, sometimes greasy feeling that might be associated with thicker, hydrating formulas. This can mean big things for anyone looking to hydrate their oily or acne-prone skin.

Ahead, board-certified dermatologists Morgan Rabach, MD, and David Bank, MD, share exactly how to use emulsions in your skincare routine.

What Are Emulsions in Skincare?

"Emulsions are lighter versions of moisturizing creams," says Rabach. "Unlike most heavy facial creams, emulsions are typically water-based, meaning they go on lighter and thinner than creams. In some cases, emulsions come in gel or almost liquid forms. I think of them as thicker than a serum but thinner than a cream."

On a scientific level, "an emulsion is a mixture of products that are not dissolvable in one another. A classic example is oil and vinegar," Bank explains. To retain their consistency, the ingredients that make up an emulsion need an emulsifier to help them stick together to form a new material. In terms of skincare, common emulsifiers include polysorbate 60, Cetearyl alcohol, and glyceryl stearate (any of which can commonly be found listed as ingredients in an emulsion)

Most emulsions are formulated as oil suspended in water, which is generally more stable and has less chance of separating than one made of water suspended in oil. This water-based formula is a fantastic option for treating any skin type, as it may not only be incredibly hydrating, but it also likely won't clog pores or leave skin feeling oily. Having a breathable complexion that's not overly coated in products probably sounds appealing to most people, regardless of their skin type, but this can be especially attractive for anyone with already oily skin who still needs to hydrate.

Benefits of Using Emulsions

• Hydrating: Emulsions work to hydrate the skin, no matter what age you are or what your skin type is.
  
• Non-comedogenic: "Emulsions offer a lighter delivery method to moisturize skin and often are non-comedogenic," Rabach explains, meaning they won't clog your pores.
• Absorb quickly: Emulsions sink into the skin's surface quickly, allowing them to act fast and deliver what they promise. "Emulsions are readily absorbed into the skin and can be more concentrated than moisturizers," Bank adds.
• Reinforce the skin barrier: According to Bank, emulsions can also reinforce the skin barrier and prevent moisture loss to make the skin healthier.
• Can be formulated with salicylic acid or hyaluronic acid: Bank says that acne-prone patients might choose an emulsion with salicylic acid, whereas those with dryness may reach for emulsions with humectant ingredients like hyaluronic acid, which binds with water molecules to hydrate the skin.

Side Effects of Using Emulsions

There are no side effects to using emulsions. "Some patients can find emulsions not moisturizing enough, and say that they need to reapply moisturizer constantly [and] it doesn't feel like it really helps," says Rabach. "Some people also find emulsions irritating."

Who Should Use Emulsion Skincare Products?

Acne-prone skin, in particular, benefits from emulsions, though "any skin type can use an emulsion," Banks assures us.

"The fact that emulsions are lighter, water-based, and more easily absorbed make them attractive to people with oily skin as a way to get the hydration your skin needs without the weight and sheen of a cream," Rabach adds. "They are especially useful for patients who are acne prone. Emulsions are also my moisturizer of choice when it's hot and humid." 

Emulsions aren't just reserved for those with oily complexions, however. People with dry, mature, or combination skin types can also experience an added boost of hydration with the help of an emulsion in addition to their moisturizer or night cream of choice. And because it's so lightweight, it won't feel too heavy when used with other products. "Dry skin can benefit as well from the hydrating properties, and a more intensive cream can be added on top for extra moisture," says Bank. "Because emulsions are so sheer, you can layer multiple products without having product build-up. If you require extra hydration, apply an emulsion before your moisturizer."

How to Use Emulsions in Your Skincare Routine

Emulsions can be used in the morning and at night, but the key to getting the most out of your emulsion is applying it as the correct step in your routine.

Generally, an emulsion should be one of the final steps, locking in any ingredients you're feeding your skin to treat specific issues. "An emulsion should be applied after the most active product," Rabach instructs. "So, if you use an antioxidant serum or a retinol first, the emulsion can be applied on top to seal it all in. You can use the emulsion under sunscreen in the morning." If an emulsion is all you need to moisturize your skin, apply it as the final step in your skincare routine (and always follow it up with an SPF if you're heading out for the day).

If you're looking for an emulsion to add to your skincare routine, there are many to choose from. Rabach recommends HA5 by Skinmedica ($124), which she says "contains a proprietary mix of five types of hyaluronic acid for immediate and long-term hydration." Bank also has a few favorites: "I like Cetaphil's Daily Hydrating Lotion with Hyaluronic Acid ($14), which is very lightweight, and Glo Skin Beauty's Oil Control Emulsion ($56) for oily-skinned patients," he says.